Liquid-lubricated roll

ABSTRACT

A liquid-lubricated roll has annular roller means rotatably supported by anti-friction bearings on an elongated axle, which may be curved or straight. To lubricate the bearings with a mist and avoid flooding them with liquid, means are provided for maintaining a selected volume of liquid in the passageway between the roller and axle so that during rotation of the roller, the liquid will form into a thin annular layer on its inner surface, which is not deep enough to flood the bearings. Projections on the axle agitate the liquid to produce a lubricating mist in the remainder of the passageway. Correct liquid volume is obtained by alternative means for removing excess liquid as the roller turns. An indication of the liquid volume can also be obtained by optical means.

Knapp et al.

[54] LIQUID-LUBRICATED ROLL [75] Inventors: George P. Knapp, Waban; Robert E.

Staples, Lakeville, both of Mass.

[73] Assignee: Mount Hope Machinery Company,

Taunton, Mass.

22 Filed: Feb. 24, 1972 [21] Appl. No.: 229,064

[52] US. Cl. 184/6.26, 29/1484 L, 184/14, 308/187 [51] Int. Cl. F16n 7/32, F16n 31/00 [58] Field of Search 184/6.26, 11 R, 13 R, 184/103 R, 14; 308/20, 187; 29/1484 L [56] References Cited UNITED STATES PATENTS 3,666,049 5/1972 Kern et a1. 184/6.26 2,950,150 8/1960 Ashworth.... 2,986,433 5/1961 Hermann 2,334,942 11/1943 Malone 184/6.26

[ 51 July 17,1973

Primary Ex aminerManuel A. Antonakas Attofney- David A. Rich, William L. Ericson et al.

[57] ABSTRACT A liquid-lubricated roll has annular roller means rotatably supported by anti-friction bearings on an elongated axle, which may be curved or straight. To lubricate the bearings with a mist and avoid flooding them with liquid, means are provided for maintaining a selected volume of liquid in the passageway between the roller and axle so that during rotation of the roller, the liquid will form into a thin annular layer on its inner surface, which is not deep enough to flood the bearings. Projections on the axle agitate the liquid to produce a lubricating mist in the remainder of the passageway. Correct liquid volume is obtained by alternative means for removing excess liquid as the roller turns. An indication of the liquid volume can also be obtained by optical means.

22 Claims, 12 Drawing Figures 9 ll] [i] 54 Patented July 17, 1973 5 Sheets-Sheet 1 Patented July 17, 1973 3,746,129

5 Sheets-Sheet 3 Patented Jul 17, W73

5 Sheets-Sheet 41' 1 LIQUID-LUBRICATED ROLL BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION Curved and straight rolls of the types conventionally used in processing paper, textiles, and other flexible sheet materials, comprise hollow annular roller means mounted by means of anti-friction bearings to rotate about elongated stationary axles, which may be straight or longitudinally curved to give the roll the desired shape. It is customary to lubricate the bearings with grease sealed between the bearing races by means of conventional retaining shields.

It would be desirable to use oil or other liquid lubricant instead of grease, as this would tend to promote longer bearing life. Furthermore, it would be feasible to operate oil-lubricated rolls at higher speeds than are suitable for grease-lubricated rolls. However, it is not satisfactory to flood the bearings with liquid lubricant, since the submergence of the rollers or balls produces turbulent splashing that consumes an excessive amount of power to turn the roll, and generates an intolerable amount of heat.

It is the primary object of the present invention to provide an improved roll which is lubricated with oil or other liquid, yet does not submerge its bearings in the liquid. It is another object to provide an improved liquid-lubricated roll which features enhanced bearing life without consuming excessive power or generating an unacceptable amount of heat. It is still another object to provide an improved roll which can operate satisfactorily at higher speeds than conventional greaselubricated rolls. Further objects and advantages of the invention will appear as the following description proceeds.

The invention is primarily concerned with rolls of a kind known per se, having an elongated axle, which may be straight or may be longitudinally curved, depending upon the intended application, as is well known in the art. A series of anti-friction bearings are spaced along the axle, usually by a series of interposed collars, and hollow annular roller means are mounted on the bearings to form the rotating working surface for engaging whatever flexible sheet material is to be handled. If the roll is curved, the roller means may comprise a series of short cylindrical spools and spaced end-to-end along the axle, each rotating on a different axis tangent to the curved axis of the axle at the location of that spool, and also includes a flexible annular surface sleeve, which is stretched over the full length of the roll and is supported by all of the spools in common.

Briefly stated, according to a preferred embodiment of the present invention, means are provided for maintaining a selected, limited volume of liquid in the annular passageway which is defined between the axle and the roller means and encloses the bearings. The volume is selected so that a thin layer of the liquid is formed on the inner circumferential surfaces of the roller means by centrifugal force as the roll turns at operational speeds, and the radial height of this rotating body of liquid extends to a level spaced radially outwardly from the axial openings between the races of the anti-friction bearings. Consequently, the rollers or balls of the bearings are not immersed in liquid, although open to the passageway.

Projections or studs are mounted on the axle and extend across the passageway slightly into the rotating body of liquid, to agitate the surface and produce a mist which fills the passageway and lubricates the bearings.

The roll is mounted with its axis horizontal. The lubricating liquid is supplied to the passageway by means of a short standpipe communicating, through a passage bored in one end of the axle, with a number of branch passages extending to the axle surface. These branch passages are circumferentially spaced apart so that at least one of them descends downwardly into the passageway to facilitate entry of liquid, regardless of the angular position in which the axle may be set. This is of particular importance for curved rolls, whose angular axle position is varied according to the degree of curvature required to affect the treated sheet material, as is well understood by those skilled in the art; but in the case of straight rolls whose axles are set in fixed positions, a single downwardly-extending passage will suffice. The standpipe also serves to vent any excess air pressure which may be created in the passageway by hydrodynamic forces, or by temperature changes in the air contained in the passageway, and which might otherwise damage liquid seals at the ends of the passageway or at least cause leakage.

Liquid-flow communication by-passing the bearings is established throughout the length of passageway by means of slots or other passage formations in the roller means, which connect portions of the passageway separated by the bearings. Since. these by-pass passages lie radially-outwardly from the bearings, continuous liquid communication is provided through the length of the roll without flooding the bearings themselves.

To regulate or set the radial height of the rotating body of liquid at the desired level, according to one embodiment, one or more scoops are mounted on the axle and extend outwardly across the passagewayto the desired liquid level. The scoops serve to shear off and drain any liquid which may accumulate above this level into branch passages which extend from the surface of the axle through its interior to one end, at which drained liquid is exhausted through a stopcock. The use of multiple drain branches spaced around the circumference of the axle is preferred because it insures that at least one of them will descend from its scoop to the drainage point, regardless of the angular position of the axle. Each branch passage forms a separate flow path extending to the drainage point, to prevent return flow into the passageway through such other branches as happen to be so oriented that they ascend from their scoops toward the drainage point. In the case of a straight roll in which there was no need to reorient the axle, the desired result would be obtainable with a single drain branch and scoop.

In another construction, the liquid level is set by allowing excess liquid to overflow a lip or orifice which is carried by the roller and extends radially inwardly to the desired liquid level. The liquid escapes through centrifugally-actuated valve means, which close when the roll is stopped to prevent loss of liquid accumulating at the bottom of the roll. The valve means may comprise a flexible annular seal, or a spring-loaded check valve, which open under centrifugal force as the roll is turned at operational speeds.

In use, a quantity of lubricating liquid somewhat in excess of calculated requirements is first added to the passageway, and the roll is rotated at operational speed for a sufficient time to level the oil into an annular body rotating with the roll on the interior surfaces of the roller means. Any excess liquid is removed by the scoops, or other level-setting means, and is drained by opening the drain stopcock. When the drainage flow ceases, the roll contains the selected volume of liquid, extending inwardly only to the radial level desired.

According to another aspect of the invention, means for giving a visible indication of the liquid level are provided. Two fiber-optic elements of a well-known kind, capable of transmitting light along their axes, however these may be bent, are inserted through one end of the axle to terminate in the passageway. An angled reflector is provided on the inner surface of the roller means, having a lip at a predetermined radial level in the passageway. Light is projected into an exposed end of one of the fiber-optic elements, whose internal tip is aimed toward a reflecting face of the reflector, preferably at right angles. The second fiber-optic element has its internal tip directed toward the overflow face at a different angle, and is preferably aimed parallel to this face. The intensity of light reflected into the second element is observable from the end of the axle, and indicates the depth, if any, of liquid partially covering the reflecting face, and consequently the presence of any excess liquid volume.

If such level-indicating means are provided, the means otherwise'used to regulate the radial height of the liquid may be omitted if desired; this function can be performed simply by opening the drain stopcock until the liquid reaches the proper level.

DESCRIPTION OF THE DRAWINGS While the specification concludes with claims particularly pointing out the subject matter of the invention, it is believed that a clearer understanding may be gained from the following description of preferred embodiments, referring to the accompanying drawings, in which:

FIGS. 1A and 1B taken together comprise a fragmentary view in front elevation and partially in crosssection of an illustrative embodiment of the improved roll, respectively showing the two opposite end portions of the roll;

FIG. 2 is a fragmentary plan view of a portion of the axle of the roll of FIG. 1;

FIG. 3 is a fragmentary sectional view of a portion of the roll of FIG. 1, shown on an enlarged scale;

FIG. 4 is a cross-sectional view of a spool forming a part of the roll of FIG. 1;

FIG. 5 is a sectional end view of the spool of FIG. 4;

FIG. 6 is a plan view of the roll of FIG. 1, illustrating curvature of theroll;

FIG. 7 is a diagrammatic end view of the curved roll of FIGS I and 6, illustrating various angular orientations of the axle which might be required in typical applications;

FIG. 8 is a fragmentary view front elevation and partially in cross-section of a modified construction,' showing only one end of the roll, with which the modifications are solely concerned;

FIG. 9 is a view in end elevation of the roll of FIG.

FIG. 10 is a fragmentary view in front elevation and cross-section of another embodiment having modified means for setting the liquid level in the roll; and

FIG. 11 is a fragmentary view in front elevation and cross-section of another construction having another means for setting the liquid level in the roll.

Referring first to FIGS. 1-6, a first form of the improved roll is indicated generally at 10, and includes an axle 12 which is longitudinally curved in the illustrated embodiment, as best shown in the plan view of FIG. 6. The curvature lies in a plane perpendicular to the plane of FIGS. 1A and 1B. The axle is supported in a stationary horizontal position by means of split clamping brackets 36 and 44 at its ends. The brackets 36 and 44 receive spherical elements 38 and 46, which permit adjustment of the angular orientation of the axle 12. The elements 38 and 46 are secured to the axle by means of set screws 40 and 48. When the axle has been set in the desired angular position, the blocks 36 and 44 are clamped against the elements 38 and 46 to fix the axle in place. a A series of anti-friction bearings 18 and 19 are spaced-along the axle by means of a group of interposed spacer collars 60, 62, 64, 66, 67, 69, 70, and 74. The stacked spacers and bearings are located axially of the roll by means of a collar 68 fixed to the left end of the axle by means of screws 72.

A threaded portion 50 at the right end of the axle 12 is threadedly engaged in the element 46. The spring spacers 74 comprise a stack of deformed annular rings, made of spring steel or the like, and are initially bent in the direction of the roll axis to form a series of circumferentially-spaced lobes extending in alternate axial directions. This subject matter forms no part of the present invention, and is described and claimed in U. S. Pat. Application Ser. No. 81,272, filed Oct. 16, 1970 by J. Douglas Robertson, for Roll With Bearing Support Means, which is assigned to the same assignee as this application. The axial compression of the spring spacers 74, and thus of the entire assembly of spacers and bearings, is adjusted prior to mounting the brackets 36 and 44 on a supporting surface, by turning the bracket 44 to thread it along the portion 50. This serves to support the inner races of the bearings 18 and 19 firmly with respect to the axle, prevents the application of excessively large compression forces when the assembly is tightened, and maintains uniform compression as the parts wear in and seat themselves.

Roller means are provided, comprising an outer annular sleeve 11 of flexible material, such as rubber or fiber-reinforced resin, suitable for the intended application of the roll. This cover is supported by an axiallyspaced series of annular spools 76 and 78, which are rotatably supported on the bearings 18 and 19. Each spool rotates on an individual axis which is tangent to the curved axis of the roll at the location of its supporting bearing or bearings. By this means, the sleeve 11 rotates in a longitudinally-curved but stable form. The sleeve is located with respect to the spools by means of a sheave 80 secured to a spool 76 by a screw 82, and an end cap 84 secured to the remaining spool 76 by a screw 85. The roll may be driven by external motive means through a belt (not shown) trained around the sheave 80, if desired; of the roll is not externally driven, the sheave may be replaced by a second plain end cap 84. If the axle 12 is to be straight, the parts 11, 76, and 78 may be replaced by a straight, rigid or flexible, annular roller.

The roller means 11, 76, 78, and the axle 12 define an annular chamber 84 between them which extends through the length of the roll but is subdivided by the enclosed bearings 18 and 19. The bearings do not have the conventional grease-retaining shields, so that the rollers or balls 83 are open to the passageway 84. The ends of the passageway are sealed by ring seals 88, 90, 92, and 94 to prevent oil from leaking out of the ends of the passageway.

For the purpose of supplying oil or other liquid lubricant to the passageway 84, a standpipe 100 is threadedly supported in a bore 20 formed in the axle 12. A series of radial bores 26, preferably four in number, is equiangularly spaced around the axle to communicate the bore 20 with the passageway 84 through aligned openings 102 formed in the spacer 64. The provision of a number of branch passages 26 insures free flow of liquid into the passageway 84 from the stand pipe 100 regardless of the angular orientation of the axle, since at least one of these passages must extend downwardly from the end of the axle into the passageway 84. The standpipe 100 additionally serves to vent the interior of the roll, and thereby prevents the application of any excessive pressure to the oil seals 88, 90, 92, and 94.

For convenience of manufacture, end portions 16 and 28 of the axle are formed separately from the central portion 17, and are subsequently connected by means of circumferential welds 24 and 32. To align the axle parts l6, l7, and 28 prior to welding them together, plugs 22 are employed.

Means for draining lubricant from the roll include a bore 30 which extends into a plurality of radial branch passages 34, preferably fourin number, which are equiangularly spaced about the axle and extend to flats 106 milled in its surface. The provision of a number of angularly-spaced passages 34 insures effective drainage of liquid in that at least one passage descends downwardly from the passageway 84 to the bore 30 regardless of the angular orientation of the axle. In this connection, FIG. 7 shows an illustrative application of the roll 10, in which sheet material 1 10 is guided over a portion of the roll surface by idler rolls 112, 114. The action of the roll on the sheet 1 10 may be varied by changing the angular orientation of the roll, as shown for example at 10' or 10", as is well understood by those skilled in the art. The provision of the branch passages 26 and 34 provides for free supply and drainage of liquidlubricant in any adjusted position.

A volume of liquid lubricant is maintained in the passageway 84 that is so regulated or selected that as the roll rotates at operational speeds, the liquid forms an annular body which rests against the interior surfaces of the roller means; but the radial height is insufficient to flood the axial openings of the bearings 18 or 19 with liquid. To provide another route than the bearings for free flow of the liquid along the length of the passageway, by-pass passages 112 are provided in the spools 78 and 76. These passages connect portions of the passageway which are otherwise separated by the bearings spacers 62, and extend radially outwardly to a height slightly beyond the level L of the rotating body' 109 of lubricating liquid, shown in FIG. 3. The studs 116 agitate the surface of the liquid and produce an oil mist which fllls the inner portion of the passageway 84 and the interior portions of the bearings 18 and 19, to lubricate the balls 83.

To regulate the radial height of the rotating body of fluid 109 at the desired level L, a number of scoops 118, preferably four in number, are equiangularly spaced about the axle. As best shown in FIGS. 1B and 2, the scoops comprise blades having surfaces which extend longitudinally of the axle and terminate at the desired radial level of the liquid body. Each of the scoops 118 is supported in a tube 120 mounted in the spacer 67, and communicate with a corresponding flexible tube'l24 through a plug 122. As the roll and the liquid body 109 revolve, the scoops shear away any liquid which exceeds the selected depth L, and this liquid is drained through the flexible tubes 124, which extend through the bore 30 into the drain cap 54. A common drain line 126 including a drain cock 128 permits ex cess liquid to be drained from the roll under manual control. It should be noted that each of the scoops 118 communicates with an independent tube 124, so that liquid draining through any tubes which descend downwardly from their scoops to the end of the roll is prevented from flowing back into the passageway 84 through other tubes which are in an ascending orientation.

In use, a supply of oil or other liquid lubricant is supplied through the standpipe 100 to the passageway 84, somewhat in excess of the quantity calculated to be required. The roll is started up and turned at operational speed for a period, typically one hour, which is sufficient to allow the oil to level out into an annulus of uniform radial height throughout the length of the roll. The drain cock l28 is then opened, and any excess of liquid is allowed to drain from the roll. This insures that the liquid has attained the selected depth, extending radially inwardly only to the level L of the scoops 118 and the studs 116. Whenever the roll is subsequently stopped, the oil will drain into the lower portions of the passageway 84, so that the bearings will be partially flooded when the roll is restored to operation. However, the liquid will once again level out into the desired annular body after a period of operation, freeing the bearings from this flooded condition.

A modification is shown in FIGS. 8 and 9 in which means are provided for inspecting the liquid level visually. It is necessary to add some additional liquid to the roll from time to time because of leakage, and a level detector indicates the correct timing and the quantity required. Parts similar to those of the preceding embodiment are similarly numbered, and only the right end of the roll is shown since the remainder is of the same construction as the roll of FIGS. l-7. A reflecting element 130 is secured to the interior surface of one of the spools 78, and provides a reflecting surface 134 extending to a lip 132 which isset at the desired radial level of the liquid body as previously described in connection with FIG. 3. The inclined reflecting face 134 becomes more or less flooded as the liquid level rises or falls. An elongated slot 133 in the adjacent spool 78 allows the liquid to flow freely past the element 130.

Two fiber-optic elements 136 and .138 of a conventional nature, and capable of transmitting light beams along their axes even though the elements are bent, are mounted in housings 140 and 137 received in suitable recesses 135 and 142 in the axle, and extend to its right end. Clamping blocks 144 and 146 secure the ends of the elements 136 and 138 in the recess 142, being fastened by screws 148. Thus, the tips 150 and 152 of the elements are visible from the end of the roll. The inner end 154 of the element 138 is bent so that it is directed at an angle to the surface 134, preferably perpendicular thereto as shown. The tip 156 of the element 136 is directed toward the surface 134 at a different angle, and is preferably aimed parallel to this surface as shown. In use, a light beam is directed into the end 152 of the element 138 so that it is caused to shine against the surface 134. In the event that the oil level is not deep enough to flood the reflecting surface, the light will reflect perpendicularly from this surface and very little will be reflected into the tip 156 of the element 136, so that the outer tip 150 will appear dark. However, when the liquid level is sufficient to partially submerge the surface 134, much of the light will be reflected off the surface of the liquid into the element 136, and will be visible at its outer tip. The intensity of the reflected light appearing at this tip is indicative of the radial depth of liquid partially submerging the surface 134.

in the construction illustrated in FIG. 8, scoops 118 are provided to regulate the liquid level in the roll. However, these may be made longer if desired; the liquid level can then be adjusted manually by opening the drain cock 128 until inspection of the level indicator element 136 shows that sufficient liquid has been drained to bring the volume in the passageway 84 to the desired level.

Another modification appearing in FIG. 8 is the provision of a leakage-collecting baffle 157, which is secured to one of the collars 69 by a set screw 158, and is formed with an internal annular chamber which drains through an exhaust line 160. A modified end cap 154 is secured to the spool 76 by screws 162, and has a frusto-conical lip 164 to direct any liquid leaking past the seal 92 intothe collecting annulus.

Another construction shown fragmentarily in FIG. 10 has a different means for setting the level L of liquid in the rotating roll. Parts similar to those of the preceding embodiment of FIGS. l-7 are similarly numbered, or are not shown. In this instance, there is an oil by-pass passage (not shown) around the end bearing 19. The scoops 1 l8 and concomitant drain means are omitted. An annular end cap 254 is secured to the spool by a screw 82, and extends into a flange forming. an outer annular lip 264 and an inner annular lip or dam 255, whose radial position determines the liquid level L. A flexible elastomeric seal 192 is carried by the: cap 254, and its lip 193 seals against a race 258 of a collector ring 257 when the roll is stationary, thereby preventing leakage of oil or'entry of foreign matter. The ring 257 is fixed on the axle 12 by a set screw 259, and also serves to locate the assembly of bearings 19 and spools 62 etc., on the axle. When the roll is turned at operational speeds, the lip 193 acts as a centrifugally operated valve and lifts from the race 258, allowing any liquid which exceeds the radial height of the lip or dam 255 to flow out of the roll and to be slung by the lip 264 into the collector ring 257, from which it is drained. The lip 255 thus sets the liquid level L at the desired height.

, Another form shown in FIG. 11 is also similar to the preceding embodiment of FIGS. l-7, except that the scoops 118 and related drain means are omitted, and means including a conduit 266 normally closed by a ball 265 serve to set the liquid level. The tube is set into a spool 69, and the radial position of its inner lip 264 determines the liquid level L. In this case, a stationary sealing rihg 94 seals the passageway 84, bearing at all times against a rotating end cap 270 mounted on a spool 69. When the roll is at rest, a compression spring 267 seats the ball 265 against the tube 266 to prevent leakage of liquid which accumulates at the bottom of the roll. However, as the roll rotates at operational speeds, centrifugal force lifts the ball 265 from its seat, any liquid in excess of the level L flows from the tube 266 and out through a passage 269 formed in the end cap, from whence it is drained into a collector ring 157. Thus the radial position of the inner end 264 of the tube 266 determines the liquid level L.

What I claim is:

l. A liquid-lubricated roll comprising:

elongated axle-forming means;

a plurality of anti-friction bearings spaced along said axle means and having openings in axial ends thereof;

annular roller means circumferentially spaced about said axle means and rotatably mounted on said bearings; said axle means and roller means defining an annular passageway extending along said axle to contain said bearings, said roller means having inner circumferential surfaces lying radially outwardly from said openings of said bearings;

means for supplying a quantity of liquid to said passageway and for setting the radial height of a rotating annular body of the liquid, formed by centrifugal force during rotation of said roller means to lie against inner circumferential surfaces of said roller means, at a pre-selected level spaced radially outwardly from said openings of said bearings;

and means for generating amist from the annular body of liquid in a radially-inner portion of said passageway which is free of the annular body of liquid, to lubricate said bearings without flooding them with liquid.

2. Apparatus as recited in claim 1, said axle being supported horizontally, said supplying and setting means including stationary scoop means carried by said axle and projecting outwardly through said passageway to said level of the rotating annular body of liquid for collecting any liquid in excess of said level, said supplying means further including drain conduit means connected with said scoop means and extending exteriorly of said roll for removing collected liquid from said scoop means, thereby to drain any excess liquid.

3. Apparatus as recited in claim 2, in which said drain conduit means extend interiorly of said axle from an end thereof and thence into a plurality of branch passages extending outwardly to the surface of said axle and terminating at different locations circumferentially spaced apart about said passageway, such that at least one of said branch passages descends downwardly from said passageway toward said end of said axle regardless of the angular orientation of said axle; there being a plurality of said scoop means circumferentially spaced apart about said passageway and each arranged to drain liquid removed thereby into a corresponding one of said branch'passages.

4. Apparatus as recited in claim 3, said drain conduit means including a plurality of separate conduits each extending from said end of said axle and into draining relation with a different one of said scoop means, whereby liquid draining into any of said branch passages oriented to descend downwardly from said passageway toward said end of said axle is prevented from re-entering said passageway through any of said branch passages oriented to rise upwardly from said passageway toward said end of said axle.

5. Apparatus as recited in claim 2, in which said scoop means have extent axially of said roll to shear any liquid from the rotating annular body of liquid which exceeds said level.

6. Apparatus as recited in claim 2, said drain conduit means including valve means operable for removing collected liquid therefrom.

7. Apparatus as recited in claim 1, said axle being supported horizontally, said supplying and setting means including supply conduit means extending interiorly of said axle from an end thereof and thence into a plurality of branch passages extending outwardly to the surface of said axle and terminating at different 10- cations circumferentially spaced apart about said passageway, such that at least one of said branch passages descends downwardly from said end of said axle toward said passageway regardless of the angular orientation of said axle, to facilitate flow of liquid into said passageway.

8. Apparatus as recited in claim 7, said supply conduit means including a stand-pipe extending upwardly from said roll to vent excess pressure from said passageway.

9. Apparatus as recited in claim 1, said mistgenerating means comprising projection-forming means fixed on said axle and extending outwardly in said passageway to a predetermined radial level in the rotating annular body of liquid, to agitate the liquid and thereby produce a lubricating mist in said passageway to lubricate said bearings.

10. Apparatus as recited in claim 1, said supplying and setting means including means for indicating the radial height of the annular body of liquid during rotation of said roller means.

11. Apparatus as recited in claim 10, in which said indicating means comprise:

a reflecting element extending inwardly from inner circumferential surfaces of said roller means to form an inclined reflecting face positioned so as to be partially submerged by said annular body of liquid;

together with means for projecting rays of light against said reflecting face, and means for observing light reflected from said reflecting face to indicate the liquid level in said passageway.

12. Apparatus as recited in claim 11, said projecting and observing means comprising fiber-optic elements constructed and arranged for transmitting light rays longitudinally thereof although bent from a straight configuration.

13. Apparatus as recited in claim 11, said projecting means being arranged to project light rays normal to said reflecting face; said observing means being directed at a different angle to said reflecting face.

14. Apparatus as recited in claim 13, said observing means being directed parallel to said reflecting face.

15. Apparatus as recited in claim 1, together with bypass passage means comprising passages formed in interior portions of said roller means and lying radially outwardly from said openings of said bearings, each bypass passage interconnecting portions of said passageway adjacent to opposite axial faces of a corresponding one of said bearings.

16. Apparatus as recited in claim 1, said supplying and setting means including lip-forming means attached to said roller means adjacent to an end of said passageway and extending into said passageway to said pre-selected level, together with means constructed and arranged for draining liquid overflowing said lipforming means from said passageway during rotation of said roll.

17. Apparatus as recited in claim 16, in which said lip-forming means comprises an annulus having a radially-inner terminus in the form of a circular lip concentric with the axis of rotation of said roller means.

18. Apparatus as recited in claim 17, together with a resilient, flexible sealing ring attached to said roller means and constructed and arranged to sealingly engage said axle means to seal said passageway against leakage of liquid when said roller means is stationary, said sealing ring being constructed and arranged to deflect under centrifugal force to disengage said axle means upon rotation of said roller means to permit flow of liquid overflowing said lip-forming means through said draining means.

19. Apparatus as recited in claim 16, in which said lip-forming means comprises conduit means communicating with said passageway at said pre-selected levelI 20. Apparatus as recited in claim 19, together with valving means for said conduit means, and biasing means urging said valving means to close said conduit means to seal said passageway against leakage of liquid when said roller means is stationary, said valving means being constructed and arranged to be opened by centrifugal force upon rotation of said roller means to permit flow of liquid overflowing into said conduit means upon rotation of said roller means.

21. Apparatus as recited in claim 16, together with centrifugally-operable valving means constructed and arranged to seal said passageway against leakage of liquid overflowing said lip-forming means through said draining means when said roller means is stationary,

and to open under centrifugal force upon rotation of said roller means to permit flow of liquid overflowing said lip-forming means through said draining means.

22. A liquid-lubricated roll comprising:

an elongated axle;

a series of anti-Friction bearings spaced along said axle and each having inner and outer races defining circumferential openings therebetween;

annular roller means circumferentially spaced about said axle and rotatably mounted on said outer races of said bearings said axle and roller means defining an annular passageway extending along said axle to contain said bearings, and enclosing the passageway at axial ends thereof;

said roller means being formed with by-pass fluid communication paths interconnecting parts of said passageway separated by said bearings to by-pass liquid flow radially outwardly around said bearings;

means forming external fluid communication with said passageway for supplying and removing lubricating liquid; 

1. A liquid-lubricated roll comprising: elongated axle-forming means; a plurality of anti-friction bearings spaced along said axle means and having openings in axial ends thereof; annular roller means circumferentially spaced about said axle means and rotatably mounted on said bearings; said axle means and roller means defining an annular passageway extending along said axle to contain said bearings, said roller means having inner circumferential surfaces lying radially outwardly from said openings of said bearings; means for supplying a quantity of liquid to said passageway and for setting the radial height of a rotating annular body of the liquid, formed by centrifugal force during rotation of said roller means to lie against inner circumferential surfaces of said roller means, at a pre-selected level spaced radially outwardly from said openings of said bearings; and means for generating a mist from the annular body of liquid in a radially-inner portion of said passageway which is free of the annular body of liquid, to lubricate said bearings without flooding them with liquid.
 2. Apparatus as recited in claim 1, said axle being supported horizontally, said supplying and setting means inclUding stationary scoop means carried by said axle and projecting outwardly through said passageway to said level of the rotating annular body of liquid for collecting any liquid in excess of said level, said supplying means further including drain conduit means connected with said scoop means and extending exteriorly of said roll for removing collected liquid from said scoop means, thereby to drain any excess liquid.
 3. Apparatus as recited in claim 2, in which said drain conduit means extend interiorly of said axle from an end thereof and thence into a plurality of branch passages extending outwardly to the surface of said axle and terminating at different locations circumferentially spaced apart about said passageway, such that at least one of said branch passages descends downwardly from said passageway toward said end of said axle regardless of the angular orientation of said axle; there being a plurality of said scoop means circumferentially spaced apart about said passageway and each arranged to drain liquid removed thereby into a corresponding one of said branch passages.
 4. Apparatus as recited in claim 3, said drain conduit means including a plurality of separate conduits each extending from said end of said axle and into draining relation with a different one of said scoop means, whereby liquid draining into any of said branch passages oriented to descend downwardly from said passageway toward said end of said axle is prevented from re-entering said passageway through any of said branch passages oriented to rise upwardly from said passageway toward said end of said axle.
 5. Apparatus as recited in claim 2, in which said scoop means have extent axially of said roll to shear any liquid from the rotating annular body of liquid which exceeds said level.
 6. Apparatus as recited in claim 2, said drain conduit means including valve means operable for removing collected liquid therefrom.
 7. Apparatus as recited in claim 1, said axle being supported horizontally, said supplying and setting means including supply conduit means extending interiorly of said axle from an end thereof and thence into a plurality of branch passages extending outwardly to the surface of said axle and terminating at different locations circumferentially spaced apart about said passageway, such that at least one of said branch passages descends downwardly from said end of said axle toward said passageway regardless of the angular orientation of said axle, to facilitate flow of liquid into said passageway.
 8. Apparatus as recited in claim 7, said supply conduit means including a stand-pipe extending upwardly from said roll to vent excess pressure from said passageway.
 9. Apparatus as recited in claim 1, said mist-generating means comprising projection-forming means fixed on said axle and extending outwardly in said passageway to a predetermined radial level in the rotating annular body of liquid, to agitate the liquid and thereby produce a lubricating mist in said passageway to lubricate said bearings.
 10. Apparatus as recited in claim 1, said supplying and setting means including means for indicating the radial height of the annular body of liquid during rotation of said roller means.
 11. Apparatus as recited in claim 10, in which said indicating means comprise: a reflecting element extending inwardly from inner circumferential surfaces of said roller means to form an inclined reflecting face positioned so as to be partially submerged by said annular body of liquid; together with means for projecting rays of light against said reflecting face, and means for observing light reflected from said reflecting face to indicate the liquid level in said passageway.
 12. Apparatus as recited in claim 11, said projecting and observing means comprising fiber-optic elements constructed and arranged for transmitting light rays longitudinally thereof although bent from a straight configuration.
 13. Apparatus as recited in claim 11, said projecting means being arranged to prOject light rays normal to said reflecting face; said observing means being directed at a different angle to said reflecting face.
 14. Apparatus as recited in claim 13, said observing means being directed parallel to said reflecting face.
 15. Apparatus as recited in claim 1, together with by-pass passage means comprising passages formed in interior portions of said roller means and lying radially outwardly from said openings of said bearings, each by-pass passage interconnecting portions of said passageway adjacent to opposite axial faces of a corresponding one of said bearings.
 16. Apparatus as recited in claim 1, said supplying and setting means including lip-forming means attached to said roller means adjacent to an end of said passageway and extending into said passageway to said pre-selected level, together with means constructed and arranged for draining liquid overflowing said lip-forming means from said passageway during rotation of said roll.
 17. Apparatus as recited in claim 16, in which said lip-forming means comprises an annulus having a radially-inner terminus in the form of a circular lip concentric with the axis of rotation of said roller means.
 18. Apparatus as recited in claim 17, together with a resilient, flexible sealing ring attached to said roller means and constructed and arranged to sealingly engage said axle means to seal said passageway against leakage of liquid when said roller means is stationary, said sealing ring being constructed and arranged to deflect under centrifugal force to disengage said axle means upon rotation of said roller means to permit flow of liquid overflowing said lip-forming means through said draining means.
 19. Apparatus as recited in claim 16, in which said lip-forming means comprises conduit means communicating with said passageway at said pre-selected level.
 20. Apparatus as recited in claim 19, together with valving means for said conduit means, and biasing means urging said valving means to close said conduit means to seal said passageway against leakage of liquid when said roller means is stationary, said valving means being constructed and arranged to be opened by centrifugal force upon rotation of said roller means to permit flow of liquid overflowing into said conduit means upon rotation of said roller means.
 21. Apparatus as recited in claim 16, together with centrifugally-operable valving means constructed and arranged to seal said passageway against leakage of liquid overflowing said lip-forming means through said draining means when said roller means is stationary, and to open under centrifugal force upon rotation of said roller means to permit flow of liquid overflowing said lip-forming means through said draining means.
 22. A liquid-lubricated roll comprising: an elongated axle; a series of anti-Friction bearings spaced along said axle and each having inner and outer races defining circumferential openings therebetween; annular roller means circumferentially spaced about said axle and rotatably mounted on said outer races of said bearings said axle and roller means defining an annular passageway extending along said axle to contain said bearings, and enclosing the passageway at axial ends thereof; said roller means being formed with by-pass fluid communication paths interconnecting parts of said passageway separated by said bearings to by-pass liquid flow radially outwardly around said bearings; means forming external fluid communication with said passageway for supplying and removing lubricating liquid; whereby lubricating liquid contained in said passageway is caused by centrifugal force during rotation of said roller means to form an annular rotating body of liquid against inner circumferential surfaces of said roller means; means for regulating the quantity of liquid contained in said passageway to maintain the body of liquid at a radial level terminating radially outwardly from said circumferential openings between said races; and projecTion-forming means fixed on said axle and extending outwardly in said passageway beyond said radial liquid level, to agitate the liquid and thereby produce a mist in said passageway to lubricate said bearings. 